1. Field of the Invention
This invention relates to traction belts for coupling to the waist of a wearer for exerting through the pelvic area longitudinal and rotational traction forces on the spine.
2. Description of the Prior Art
Traction belts, such as the ones disclosed by Varco in U.S. Pat. No. 2,638,091, and Kilbey in U.S. Pat. No. 3,587,570, are well known in the art. Pelvic traction belts of this type are adapted to be placed around the waist for engaging the crest of the hip bones of the wearers. The old belts are fitted with extension straps to be connected to weights for providing a tension force against the spinal vertebrae through the pelvis of the patient. This tension force provides only a local immobilization of the central torso area and therefore leaves the other appendages of the patient free for other activities. Beard, in U.S. Pat. No. 3,572,327, discloses a belt of similar design. These pelvic traction belts employ tension straps on the side, the front or the posterior portions of the belt for applying longitudinal tension on the spinal column. However, all of these designs require that webbing straps be sewn to the circumferential section of the pelvic traction belt, a manufacturing process which is expensive, time consuming and unnecessarily subject to failure. After a period of nominal use the tension force pulling at the stitches causes the circumferential section of the pelvic traction belt to wrinkle, bunch up and bind, thus causing discomfort to the wearer. After additional periods of use the stitching begins to separate from the belt, later resulting in the ultimate separation of the strap from the circumferential belt.
Wiltrout, in U.S. Pat. No. 2,966,906, discloses a pelvic traction belt of advanced design which utilizes a plurality of straps communicating between different portions of a circumferential belt to provide additional strength thereto. The tension straps are coupled directly to the strengthening straps which communicate about the belt, thus alleviating the necessity for stitching the tension straps directly to the circumferential belt. However, this design requires complex procedures for fitting the circumferential belt and the harness to each individual patient. Furthermore, the excessive use of straps and harnesses on the rear of the belt provides bumps and lumps which produce substantial discomfort to some patients after prolonged periods in the reclining position.
Other traction devices are disclosed by Sloan in U.S. Pat. No. 590,531, Hien et al in U.S. Pat. No. 2,553,969, Burrus in U.S. Pat. No. 875,046, and Storms in U.S. Pat. No. 810,580.
In contrast to the prior art pelvic traction belts, the present invention applies both a longitudinal traction force and a rotary traction force to the human pelvis for transmission to the spinal column. These forces are incident upon the back of the pelvic region, thus reducing the friction between the patient's garments and the bed sheets. This design is more efficient in controlling the abnormal excessive curvature of the lumbar spine than the heretofore used belts, which employ side strap and back strap designs, because of the more even distribution of traction forces throughout the fibers of the new belt. Furthermore, the design of the present invention lends itself to an ease and economy of manufacture since the belt is constructed of essentially one piece of a lightweight material. This design lends itself to a reduction in stock and inventory since one or two sizes of the pelvic traction belt fit the greater majority of all patients. The present design also requires a minimum of adjusting when the belt is fitted to the patient, and not unimportantly minimizes the time required for disengagement of the belt from the traction force for allowing the patient to quickly care for other personal needs.